A pigeon breeder wants to apply artificial selection to develop pigeons with a specific body shape and feather pattern. For the breeder to be successful, what property must exist among the breeding stock of pigeons?

Artificial selection can be described as an effective process which humans use to produce plants and animals with desirable traits. In this process, parents with desirable traits are bred together to produce offspring's with desirable traits. The method of artificial selection has been used by farmers for a long time and it is one of the most ancient techniques of biotechnology.

The pigeon breeder must have pigeons with desired shape and feather. These pigeons can be bred together to get offspring with the desired trait.